I have recently tried NSO's ordering system which was the nsohelpline.com. This system aims for convenience and for those citizens who are a busybee. This in fact delivers our certificates at our doorsteps. However, the downside was that it costs more than what is normally charge. For this transaction, I have ordered a copy of NSO certified marriage certificate which cost me Php 350 compared to what is normally charge of Php 140 plus say Php...
